Microbial Mitomycin

Screening of microbial products has led to the discovery of a number of growth-inhibiting compounds that have proved to be clinically useful in cancer chemotherapy. Many of these antibiotics bind to DNA through intercalation between specific bases and block the synthesis of RNA, DNA, or both cause DNA strand scission and interfere with cell replication. All of the anticancer antibiotics now being used in clinical practice are products of various strains of the soil microbe Streptomyces. These include the anthracyclines, bleomycin, and mitomycin. 

Microbial sources have been a very rich source for cancer chemotherapeutic agents. Of particular note is the Strep-tomyces spp., which has been responsible for the production of many approved anticancer agents that are in clinical practice. These agents are represented by highly diverse structural classes exemplified by the anthracycline family (e.g., doxom-bicin, 73) (72-74), actinomycin family (e.g., dactinomycin, 74), glycopeptides family (e.g., bleomycins A2 and B2, 75 and 76) (75), and mitomycin family (e.g., mitomycin C, 77) (72, 76). All these compounds specifically interact with DNA for then-mode of action. 

Most of the important antitumor compounds used for chemotherapy of tumors are microbially-produced antibiotics. These include actinomycin D, mitomycin, bleomycins and the anthracyclines, daunorubicin and doxorubicin. The recent successful molecule, taxol (=paclitaxel), was discovered in plants but also is a fungal metabolite. It is approved for breast and ovarian cancer and is the only antitumor drug known to act by blocking depolymerization of microtubules. In addition, taxol promotes tubulin polymerization and inhibits rapidly dividing mammalian cancer cells. It also inhibits fungi such as Pythium, Phytopthora and Aphanomyces spp. by the same mechanism. ... 

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